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(ModeL) G. F. HOUCK.

MECHANICAL CALCULATOR.

" No. 249,621, Patented N0v. 15, 1881.

' UNITED STATES PATENT OFFICE.

GEORGE F. HOUOK, ()F WARRENSBURG, MISSOURI.

MECHANICAL CALCULATOR.

SPECIFICATION forming part of Letters Patent No. 249,621, dated November 15, 1881. Application filed J une 21, 1881. (ModeL) To all whom it may concern:

Be it known that I, GEORGE F. HoUoK, a citizen of the United States of America, residing at Warrensburg, in the county of Johnson and State of Missouri, have invented certain new and useful Improvements in Mechanical Calculators; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The nature of my invention consists in the construction and arrangement of an instrument for mechanically calculating the difference between the gross and net weight of a quantity of merchandise, and stating such difference in bushels and fractions of a bushel.

In the accompanying drawings. Figure 1 is a plan view of my mechanical calculator, and Fig. 2 is a sectional view through the center.

In these drawings, A A represent the base of the calculator, upon which is attached the circular disks B B and F F, which turn upon the pivot 0. These disks are so pivoted that in revolving the large, B B, just touches the plane of the base, and the smaller one, F F,

0 just touches the larger one.

A stationary index, S, is made fast to the block D. The small disk F F has an index, 19, and both disks are provided with projecting studs G and H, for handles to turn them by. These parts may be made of wood or metal and of any suitable size. The periphery f f f of the disk F F is divided into two hundred and forty equal parts, of which only every tenth one is marked on the drawings. These divisions are numbered from the index 19 around to theleft, as 10, 20, 30, &c.

The disk B B is marked by aseries of circles, one set being continuous lines and the others dotted lines. The circle a a or, nearest the edge of the disk F F, is also divided into two hundred and forty equal parts or spaces, and numbered from the zero mark, which may be at any point, around to the right, as at 10, 20, 30, &c. The other figures upon the disk are the calculations for changing pounds to bushels, the circle I) b being in this case for wheat, d d for coal, and c c for corn. These sets of numbers, running to 240, are used for subtraction, and at the same time pointing out the net amount of the article weighed in bushels. The calculations on these drawings are only carried out for numbers up to 240. They may be carried to any desired number by dividing the circles in the required number of equal parts.

Arranged around the circle a of the disk B are the numbers of the minuend, and around the disk F the figures of the remainder or net weight. Upon the circles b, c, and d of the disk B are arranged the results of the subtraction in bushels and fractions of a bushel, and which will be correctly indicated under the index S at the termination of each operation.

The figures on the circle a of the disk B, and the figures arranged around the disk F, are the calculating quantities of the device stated in pounds The gross weight of a given quantity of merchandise'is represented by the corresponding amount in thecircle a, and the net weight by a like amount upon the disk F. The tare or result is, after the manipulation of the disks hereinafter to be described, indicated upon the circle a, and in bushels and fractions of a bushel upon the circles b, c, and d correspond- 1n g.

To illustrate more clearly the operation of my calculator, it is desired to ascertain the 11 um her of bushels of wheat lost from a quantity weighing two hundred and twenty pounds, and which,aftertheloss,weighs but seventypounds. Two hundred and twenty pounds is the gross weight or minuend, seventy pounds is the net weight. I register the gross weight (two hundred and twenty) under the index S. I then register under the same index the net weight, (seventy) I next move the disk B around until the gross weight (two hundred and twenty) registers under the index 19, the disk F remaining stationary during this manipulation. The operation is then complete, and by referring to the circle a the result will be found registered under the index S-viz., loss one hundred and fifty pounds. Then by referring to the circle b it will be seen that the loss in bushels and fractions of a bushel is two and one-half. Had the article been corn, the circle 0 would show that two and one-seventh bushels had been lost; if coal, by reference to the circle (I, one and seven-eighths bushel would be indicated as the loss.

The advantage of using such an instrument is that it avoids making the divisions necessary to change pounds to bushels, since to do that one must divide the number of net pounds by the number of pounds in a bushel.

What I claim as my invention, and desire to secure by Letters Patent, is-

A mechanical calculator consisting of the disks B and F, pivoted to the base A, provided with index-points S and p, and having upon them an arrangement of figures and circles, as

shown and described, to calculate the difference between the gross and net weight of a given quantity of merchandise, and adapted to state the same in bushels and fractions of 15 a bushel.

In testimony whereof I affix my signature in resence of two witnesses.

GEORGE F. HOUCK.

Witnesses:

S. J. BURNETT,

, HARVEY SWINDLER. 

